Control apparatus for circular knitting machine

ABSTRACT

In a circular knitting machine a mechanical programming device for controlling the operation of the electronic computer by which the operation of the chain and control drum are carried out. The mechanical program carrier is a cylinder having an operative surface on which an adjustable program may be stored. The storage of the program is obtained by the use of pins selectively positioned in holes arranged in a plurality of parallel rows. The program carrier is mounted so as to have its operational surface movable correspondingly to the course of rotation of the knitting machine control drum. The program carrier is thus periodically turned by an indexing device. The number of indexes corresponds to the number of rows of the stored program on the program carrier. Pivotable levers adapted to scan or engage the programming means are provided. The levers are arranged with a corresponding switch so that the switches are closed by the motion of the scanning levers. The switches are connected to the individual memory members in the counter components of the electronic computer.

United States Patent [191 Kouklik et al.

[4 1 Jan. 21, 1975 1 CONTROL APPARATUS FOR CIRCULAR KNITTING MACHINE [75] Inventors: Ivo Kouklik; Pavel Uhlir, both of Trebic, Czechoslovakia [73] Assignee: Elitex Zavody Textilniko Strojirenstvi generalni reditelstvi, Liberec, Czechoslovakia [22] Filed: Mar. 20, 1973 [21] Appl. No.: 342,941

[30] Foreign Application Priority Data OTHER PUBLICATIONS The Hosiery Trade Journal, Nov. 1965, pp. 183-185.

Primary Examiner-Wm. Carter Reynolds [57] ABSTRACT In a circular knitting machine a mechanical programming device for controlling the operation of the electronic computer by which the operation of the chain and control drum are carried out. The mechanical program carrier is a cylinder having an operative surface on which an adjustable program may be stored. The storage of the program is obtained by the use of pins selectively positioned in holes arranged in a plurality of parallel rows. The program carrier is mounted so as to have its operational surface movable correspondingly to the course of rotation of the knitting machine control drum. The program carrier is thus pcriodically turned by an indexing device. The number of indexes corresponds to the number of rows of the stored program on the program carrier. Pivotable levers adapted to scan or engage the programming means are provided. The levers are arranged with a corresponding switch so that the switches are closed by the motion of the scanning levers. The switches are connected to the individual memory members in the counter components of the electronic computer.

3 Claims, 3 Drawing Figures PATENTH] JANZI I975 SHEET 1 BF 2 CONTROL APPARATUS FOR CIRCULAR KNITTING MACHINE BACKGROUND OF INVENTION The present invention relates to the control of circular knitting machines.

Circular knitting machines are common in which the operation of the needle cylinder and the knitting instrumentalities is regulated by a predefined program stored on a control drum. The drum is periodically turned about its axis from sector to sector exposing the corresponding pattern for the knitwork. The control drum is itself turned by a pushing mechanism associated with an extending contact link on an endless chain which is periodically advanced in relation to the rotation of the needle cylinder. The course of the indexing of the chain is further controlled by an electronic computer having a pre-determined stored program and a cooperating mechanism which blocks the movement of the chain for a predefined interval corresponding to the length of the corresponding section of the knitwork being made. Such device is arranged so that at the point between two link contacts on the chain, the indexing means for the chain is prevented from engaging and thus the chain is stopped in its movement, although the needle cylinder continues to turn, for as long as the interval is programmed into the electronic computer. The electronic computer generally comprises an adjustable digital switch or timing switch which switch is interposed in a control circuit for processing the information given by it and by the operation of the needle cylinder. The electronic computer also includes means for stepping from one digital switch to another so that each of the particular sections of the knitwork in which a change in operation is required can be controlled by a separately adjustable digital switch. Thus the sections of the knitwork as for example the leg and sole portions of a ladies stocking can be independently regulated.

When knitting, for example, a long ladies stocking, the chain is composed so that there are approximately ten fields of smooth links between each of the contact links along the chain. That is there are at least ten sections wherein the chain is indexed in uniformed manner between the contact links which actuate the transition or change in the knitwork operation. As a result the chain had to be excessively long. Recently an improvement in the electronic computer has provided for the use of a number of switch circuits corresponding to the number of fields of smooth links on the chain, so that the switch circuits could be made to store the interval corresponding to the length between the limiting contact links and thereby the number of smooth links could be removed from the chain and the chain made smaller. However, since the production of an electronic computer employing a large number of switch circuits is quite expensive only certain smooth fields of the chain were chosen for replacement. In general only three were so replaced, those corresponding to the production of the welt, the leg, and the sole of the stocking were most frequently chosen. In the copending application serial No. 342,985, filed on even date herewith, corresponding to Czechoslovak patent application PV 1,844/72 dated Mar. 20, 1972, held by the common assignee herewith, there is shown and described an electronic computer device of this type. The advantage of the devices of this type consists in that it enables a very quick transition from one section of the length of the LII knitwork to another section of the knitwork and permits the formation of very long hose and other knitworks having sections of great length.

In the operation of the knitting machines as aforedescribed, small failures may take place wherein the knitwork is slightly damaged as for example by the creation of a loose loop, or a miss loop caused by the existence of a faulty needle. Such failure is found by sensing devices which stop the machine automatically, however the attending mechanic must change the bad needle and then cause the machine to restart. As however the knitwork which is on the machine is itself'damaged it is undesirable to finish it as it would create a needless loss in time and in excessive material consumption. Therefore in most cases it is necessary to manually restart the machine whereby the knitwork cycle is shortened and the material consumption is reduced. The manual starting is performed by the mechanic who waits for the machine to automatically cycle until the control lever of the-indexing mechanism connecting the control drum with the chain falls from its contact with the contact link on the control chain. Only then can the mechanic manually turn the chain and thus the machine pass the field of smooth links until the follow ing contact link is reached and adjusted. The contact which is adjusted in this manner is then shifted mechanically so that the control lever is again lifted and the further push of the control drum is performed. This operation is repeated by the mechanic until the control drum is completely turned to its starting section so that the beginning of a new knitting cycle can be automatically obtained. The manual turning of the chain is very difficult and requires great skill on the part of the mechanic. Further the time saved in manually turning the control drum is not much of a saving over the costs in time and effort on the part of a skilled mechanic.

It is an object of the present invention to provide a control means for circular knitting machines which mitigates the disadvantages of the prior art and provides an improved system thereover. It is a further object of the present invention to provide a control mechanism for circular knitting machines which is simple and reliable in its operation and which permits a more economical operation of the knitting machine.

These objects, other objects, and the numerous advantages of the present invention will be seen from the following disclosure.

SUMMARY OF INVENTION Briefly according to the present invention the circular knitting machine is provided with a mechanical programming device for controlling the operation of the electronic computer by which the operation of the chain and control drum are carried out. The mechanical program carrier is a cylinder having an operative surface on which an adjustable program may be stored. Preferably the storage of the program is obtained by the use of pins selectively positioned in holes arranged in a plurality of parallel rows. The program carrier is mounted so as to have its operational surface movable correspondingly to the course of rotation of the knitting machine control drum. The program carrier is thus periodically turned by an indexing device. Preferably the number of indexes corresponds to the number of rows of the stored program on the program carrier. Pivotable levers adapted to scan or engage the programming means are provided. The levers are arranged with a corresponding switch so that the switches are closed by the motion of the scanning levers. The switches are connected to the individual memory members in the counter components of the electronic computer.

As a result of the present invention an electronic computer is provided which enables the replacement and the removal of the smooth links of the chain without the corresponding use of the digital switch circuits. Furthermore the automatic return of the control drum to its starting position so that a new cycle of knit-work can be immediately started is facilitated.

Full details of the present invention are set forth in the following description and are shown in the attached drawings.

BRIEF DESCRIPTION OF DRAWINGS In the accompanying drawings:

FIG. 1 is a schematic view of the mechanical operating means controlling the indexing of the control chain and the control drum on which the wiring of the electronic computer is shown,

FIG. 2 is an enlarged detail of the mechanical programming device and its connection to the control drum, and

FIG. 3 is a flow diagram of the electronic computer circuits showing the elements thereof.

DESCRIPTION OF INVENTION Turning first to FIG. 2, the control drum 1 of an otherwise conventional circular knitting machine of the type herein under discussion is provided on its outer surface with a plurality of segments 2. The segments 2 are adapted to be engaged and control the movement ofa lever (not shown) which in turn is adapted to actuate the operating knitting instruments of the machine. The control drum 1 is provided with an indexing mechanism comprising a fixed ratchet wheel 3 the teeth of which is adapted to be engaged by a pawl 4 which as seen in FIG. 1 is pivotally mounted about a pin 5 at the end of a pushing lever 6. The pushing lever 6 is pivotally mounted at its center about a stationary pin 7 and has at its outer end a roller 8 mounted about a pin 9. The roller 8 follows the surface of a cam 10 and is pressed against the surface by a tension spring 11 which is fastened at one end to the machine frame 12.

As seen in FIG. 2 the control drum is elongated, in accordance with the present invention provides program carrier 13 extending as a cylindrical body axially from the ratchet wheel 3. The program carrier 13 is cylindrical and is provided about its circumference with holes 14 into which are mounted programming pins 15. The holes 14 are arranged in parallel rows along the axis of the program carrier 13 (with the axis of control drum 1). Each row of holes 14 corresponds to one turn or index of the control drum so that the number of rows of holes 14 on the program carrier 13 equal the number of teeth on the ratchet wheel 3. The program carrier itself is elongated for a length sufficient to contain a number of holes in each row capable of obtaining the program necessary for the operation to be described herein.

Adjacent the program carrier 13 there is mounted a plurality of two arm or bell crank levers 15'. One arm of the bell crank levers l5 overlies the surface of the program carrier 13 while its other arm cooperates with a corresponding switch 16 mounted on the machine frame. In addition to the bell crank levers 15' an additional bell crank lever 17 is mounted adjacent the program carrier 13. This lever 17 is adapted to cooperate with only one pin 18 which pin is positioned to correspond to the position of the control drum at the begin ning of the knitting operation. Thus the pin 18 defines the beginning of the knitwork program. The lever 17 cooperates with a switch 19 which may also be manu ally operated. The switch 19 is connected into the circuit of an electronic computer shown generally by the numeral 20 in FIG. 1. The computer 20 is also controlled by a switch 21 and a switch 22. The computer 20 consists of a pulse generator 23 providing a driving pulse for a counter 24 of higher order and a counter 25 of lower order. The counters 24 and 25 contain a plu rality of memory members such as magnetic storage devices or transitorized storage devices each of which is connected by a line A via a terminal board 26 to the switches 16. The switch 19 is actually connected to an amplifier 27 by which the signal pulse output from the counters 24 and 25 are amplified and squared and forwarded to the mechanical operating means such as the electromagnet 28 by which the indexing of the chain is prevented. The switch 19 is connected by a line C to the terminal board at 26. The starting or initiation of the electronic computer 20 is controlled by still another switch 29 connected to the pulse generator 23 by which the counters 24 and 25 are driven. The counters at 24 and 25 are conventional circuits which count input pulses and which produces one output pulse each time it receives some pre-determined number of input pulses. Such counter circuits may be connected in cascade to provide digital counting if desired.

The indexing mechanism or pushing means for the control drum 1 is operated by a two armed lever 30 mounted at its central pivot axis 31. One end of the lever 30 cooperates with a transversely extending sliding block 32 mounted at the end of the pawl 4 while the other end of the lever 30 is adapted to engage the link contacts 33 mounted on the control chain 34. Mounted about pivot 31 is a bell crank 35 one arm of which is adapted to cooperate with an extending contact 36 also mounted on a chain 34. The contact 36 is arranged adjacent to the contact 33 and is slightly larger. The other end of the bell crank 35 is adapted to control the switch 29 when it is pivoted. The chain 34 is mounted about two pulley wheels 37 and 38. The pulley wheel 37 is provided with an indexing mechanism comprising a fixed ratchet wheel 39 which is itself engaged by a pawl 40 which is mounted pivotally about a pin 41 fixed at the end of a two armed lever 42 pivoted at its apex about a shaft 43. At the free end of the lever 42 there is fixed a pivot pin 44 on which is freely mounted a cam follower roller 45. The roller 45 follows the contoured surface of a rotating cam 46 which is connected mechanically to the needle cylinder. A tension spring 47 mounted at one end on the machine frame biases the lever 42 so that the roller 45 is in constant engagement with the cam 46. The cam 46 is adapted to rotate in relation to the rotation of the needle cylinder itself at the same speed as cam 10 and at a ratio with the needle cylinder of l :2 so that one step of the counting chain (control drum) equals two revolutions of the needle cylinder. The outer arm of the push lever 42 is provided with an extending finger 48 which cooperates with the switch 21 which is mounted adjacent to it. The operation of the pawl 40 is controlled by the mechanical stop means comprising the magnet at 28. The magnet 28 has a movable armature 49 which is biased into a normal outward position by a spring 50. In its normal position the pawl 40 is allowed to engage the teeth of the ratchet wheel 39 when however the magnet 28 is activated and the armature 49 retracted into it the pawl 40 is lifted out of contact with the teeth.

The device described operates as follows:

On rotation of the needle cylinder (not shown) the cam 46 rotates causing the push lever 42 to swing back and forth. As the push lever 40 moves clockwise as seen in the figure the pawl 40 engages the ratchet wheel 39 and causes the chain to be advanced periodically in the direction of the arrow S. As the chain is advanced, the contact members 33 and 36 are brought sequentially beneath the arms of the levers 30 and 35. Since the bell crank lever 35 extends beyond the edge of the outer arm of the lever 30 the contact member 33 is caused to engage the lever 30 first. The contact member 33 lifts the lever 30 which then turns about its pivot point 31 so that its outer arm drops counterclockwise. This permits the slide block 30 and the pawl 4 to also drop so that the pawl engages with the teeth of the ratchet wheel 3 mounted on the control drum 1. The pawl 4 is mounted at the end of the rocking lever 6 which is continuously rocked by action of the cam 10 consequently as the pawl 4 engages the ratchet wheel 3 the control drum 1 together with the program carrier 13 is caused to index or turn in the direction of the arrow S1 (FIG. 2). Because of the correspondence of the teeth in the ratchet wheel 3 and the rows of holes 14 and pins 15 in the program carrier, the carrier 13 is turned for only one row of pins. Thus allowing the program carrier 13 to remain stopped and fixed at the newly adjusted row of programming means 14, 15 adjacent the corresponding scanning levers 15'. The scanning levers 15' corresponding to those which engage the program pins 15 are lifted and swung clockwise as seen in the figures so that the appurtenant switches 16 are closed. In this manner the information recorded on the program carrier 13 are fed via line A into the corresponding parts of the memory cores of the counters 24 and 25 of both higher and lower order. The pins 15 represent the number of pushes or movements necessary to advance the control chain 34 in any particular section. Upon the further motion of the control chain 34 in the direction of the arrow S, the lever 30 is caused to slip and fall from the contact member 33 which moves out of its way. As a result the lever 30 has its free end lifted clockwise so that it again engages the sliding block 32 lifting the pawl 4 from engagement with the ratchet wheel 3 of the control drum. Consequently this information is transferred and recorded into the fixed memory cores. After this recording of the information, the contact link 36 adjacent to that of the first contact 33 comes into engagement with the end of the bell crank lever 35 causing it to turn counterclockwise as seen in the drawings. The other end of the bell crank 35 then closes the switch 28 and thus the circuit of the electronic computer 20 is completed. As a result power is fed into the electro-magnet 28 so that the armature is withdrawn against the bias of the spring 50 to lift the pawl 40. On the lifting of the pawl 40 the control chain 34 ceases to be advanced since the operation of the indexing means is interrupted. The cam 46 which is connected to the needle cylinder continues its rotation and continues to swing the push lever 42 which periodically and rhythmically closes the switch at 2.1. The closing of results in a sensing or scanning of the number of revolutions of the needle cylinder. Which causes the pulse generator 23 to provide a driving pulse to the counters 24 and 25 which then causes a shifting of the information about the number of revolutions on to the memory cores of these counters. As soon as the number of revolutions scanned by the scanner 21 corresponds and is in accord with the number of revolutions set into the program by adjustment of the pins 15, the counters 24 and 25 produce an output signal which is transferred to the amplifier 27. The amplifier 27 is then shut down causing a de-energization of the electromagnet 28. On the de-energization of the electromagnet 28 the pawl 40 drops onto the teeth of the ratchet wheel 39 by action of the spring 50 so as to restart the advancement of the control chain 34.

As will be seen above the chain 34 is halted in its ad vancement for a period of time determined by the program established on the program carrier 13. Thus the smooth links which normally constitute the field between the two contacting link members of the chain 34 may be replaced by the fixed program on the program carrier 13 which program may of course be selectively adjusted by placing the pins 15 in any one of the selected holes 14 in any particular row.

In the further course of movement in the chain 14, the lever 35 falls and slips from the contact member 36 thus causing the bell crank lever 35 to allow the switch 29 to open and the circuit of the electronic computer 20 is also interrupted. The computer 20 remains out of action until a following contact member 33 and 36 interposed on the chain 34 at spaced intervals from the first such contacts comes into engagement with the levers at 30 and at 35 and repeats the entire cycle as described above.

Should the machine fail for any reason the movement of the needle cylinder is stopped either automatically or manually by the attendant or mechanic supervising the machine. The stopping of the needle cylinder also stops the movement of both cams 10 and 46 which thus prevents the indexing of either the chain 34 or the programming carrier 13. After removing the failure. the normally closed switch 19 is opened and the circuit to the electronic computer 20 is interrupted and placed out of operation. As a result no power can be caused to flow through the electromagnet at 28 and consequently on restarting of the needle cylinder the control chain 34 thus also the control arm 1 and the program carrier 13 are caused to rotate continuously until the starting position of the machine is reached. At this point the pin 18 engages the scanning lever 17 which then actuates the switch 19 placing it back into action whereupon the circuit of the electronic computer 20 is again closed and automatic operation of the electromagnet 28 can proceed. From this starting position the new knitwork can be begun and completed from its initial point.

From the foregoing it will be seen that the advantages of the present invention are easily obtained in that the chain can be substantially shortened by the removal of the fields of otherwise smooth links and replaced by a program carrier without the use of digital switches which are themselves very expensive. Furthermore the present invention provides for the automatic returning to the start of the program knitwork cycle without the need of manually turning the control drum. Various changes in modifications may be made by those skilled in this art in addition to those suggested herein. Accordingly, it is intended that the present disclosure be illustrative only of the present invention and not limiting of it.

What is claimed is:

1. In a circular knitting machine provided with a control chain having an indexing mechanism for advancing said chain relative to the number of revolutions of the needle cylinder, a control drum having an indexing mechanism for turning said drum, the interval for indexing the control chain being controlled by the output of counters of an electronic computer having memory storage members providing a predefined program of operation in relation to the rotation of the needle cylinder operating a mechanical means by which the indexing of said chain is prevented during the given interval, said machine including a mechanical programming device for controlling the operation of the electronic computer comprising a program carrier having an active surface on which means for storing an adjustable program is provided, means for mounting said carrier so that the movement of the active surface corresponds to the rotation of the control drum, a plurality of pivotable levers scanning the means storing the adjustable program contained on the surface of said program carrier and switches arranged to be contacted by said levers when engaged by said adjustable program, said switches being connected to the memory members of the counters of the electronic computer.

2. The circular knitting machine according to claim 1 wherein a manually operable switch is arranged in the circuit of the electronic computer said switch being operable by programming means mounted on the programming carrier placed in a position corresponding to the position of the control drum at the beginning of the knitting operation.

3. The circular knitting machine according to claim 1 wherein the program carrier comprises a cylindrical body arranged coaxially with the control drum and being fixedly mounted for conjoint rotation therewith, the means for storing the adjustable program comprising a plurality of cooperating holes and pins insertable therein, the holes being arranged on the outer surface of said cylindrical body in rows corresponding to the number of turns through which the control drum may 

1. In a circular knitting machine provided with a control chain having an indexing mechanism for advancing said chain relative to the number of revolutions of the needle cylinder, a control drum having an indexing mechanism for turning said drum, the interval for indexing the control chain being controlled by the output of counters of an electronic computer having memory storage members providing a predefined program of operation in relation to the rotation of the needle cylinder operating a mechanical means by which the indexing of said chain is prevented during the given interval, said machine including a mechanical programming device for controlling the operation of the electronic computer comprising a program carrier having an active surface on which means for storing an adjustable program is provided, means for mounting said carrier so that the movement of the active surface corresponds to the rotation of the control drum, a plurality of pivotable levers scanning the means storing the adjustaBle program contained on the surface of said program carrier and switches arranged to be contacted by said levers when engaged by said adjustable program, said switches being connected to the memory members of the counters of the electronic computer.
 2. The circular knitting machine according to claim 1 wherein a manually operable switch is arranged in the circuit of the electronic computer said switch being operable by programming means mounted on the programming carrier placed in a position corresponding to the position of the control drum at the beginning of the knitting operation.
 3. The circular knitting machine according to claim 1 wherein the program carrier comprises a cylindrical body arranged coaxially with the control drum and being fixedly mounted for conjoint rotation therewith, the means for storing the adjustable program comprising a plurality of cooperating holes and pins insertable therein, the holes being arranged on the outer surface of said cylindrical body in rows corresponding to the number of turns through which the control drum may be indexed. 